Public water system · CA4910023
ActiveCalifornia-American Larkfield (Puc)
At a glance
California-American Larkfield (Puc) (PWSID CA4910023) is an active community water system in Sonoma County, California. It reports serving 7,913 people through 2,398 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in July 1998.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,913
Service connections
2,398
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does California-American Larkfield (Puc) compare with other water systems in Sonoma County?
By EPA's size categories, California-American Larkfield (Puc) is a medium system (3,301 to 10,000 people). Sonoma County has 441 active public water systems. Its population served is about 7.2 times the county average of 1,092 people per system, and accounts for 1.6% of the 481,435 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so California-American Larkfield (Puc) is about 18% above that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates California-American Larkfield (Puc)?
EPA lists California-American Larkfield (Puc) as privately owned. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 371 of the 441 active systems in Sonoma County (84%) are also privately owned.
Does California-American Larkfield (Puc) have drinking water violations?
EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in July 1998. The violations listed here began between August 1988 and July 1998. By type: 1 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved is Total coliform bacteria (TCR). EPA lists 1 as resolved and 1 as archived. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1988-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 2 violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
California-American Larkfield (Puc): frequently asked questions
Who runs California-American Larkfield (Puc)?
California-American Larkfield (Puc) (PWSID CA4910023) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does California-American Larkfield (Puc) serve?
California-American Larkfield (Puc) reports serving 7,913 people through 2,398 service connections in Sonoma County, California.
Where does California-American Larkfield (Puc) get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does California-American Larkfield (Puc) have any drinking water violations?
EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in July 1998. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is California-American Larkfield (Puc)'s water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in July 1998. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find California-American Larkfield (Puc)'s water quality report?
As a community water system, California-American Larkfield (Puc) must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Sonoma County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Santa Rosa, City of | Sonoma | 175,396 | Community | Groundwater |
| Petaluma, City of | Sonoma | 60,781 | Community | Groundwater |
| Rohnert Park, City of | Sonoma | 43,821 | Community | Groundwater |
| Windsor, Town of | Sonoma | 25,561 | Community | Groundwater |
| Valley of the Moon Water District | Sonoma | 23,107 | Community | Groundwater |
| Sonoma, City of | Sonoma | 11,725 | Community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “California-American Larkfield (Puc), PWSID CA4910023, California”, https://aquacensus.com/water-systems/california/california-american-larkfield-puc-ca4910023 (data as of October 1, 2026).